Sorry, you need to enable JavaScript to visit this website.

March Madness: What Weed Control Options make Sense

Published on: 19:10PM Mar 25, 2010

March madness this spring has cherry trees in full bloom, and apple blossoms ready to pop open. Recent above average temperatures have hastened the arrival of spring and now wheat growers are hoping for April showers for their wheat fields. With April 1st coming just next week, growers are also facing a cutoff date of applications of some herbicides especially in Milton-Freewater and the adjacent Walla Walla Valley areas.

A quick check with MiltonFreewater fruit and grape growers today, indicates that leaves are starting to emerge on horticultural crops in the Walla Walla Valley, which raises the need for additional care to be taken as herbicide applications on wheat as other crops are ahead of “normal” development. Grapes continue to be the most sensitive crop found in the area. Herbicide drift can injure foliage, shoots, flowers and fruits. If injury is severe enough, or occurs repeatedly, it can cause reduced yield, poor fruit quality, and occasionally, vine death.

For downy brome control, Powerflex and Olympus Flex are good choices. Powerflex offers a 9 month plantback restriction which offers some flexibility in future planting decisions. Dan Ball, OSU Weed Scientist recommends a full 3.5 oz rate for a spring application of Powerflex. It has good crop safety, and while he has noted some yellowing with Powerflex under cool application conditions but he hasn’t seen this to affect yield.

Table 1. Alternative herbicides for wheat less likely to injure grapes.

Axial
Hoelon
Olympus
Buctril
Huskie
Olympus Flex
Discover
Linex
Paramount
diuron (Karmex)
Maverick
PowerFlex
Everest
metribuzin (Sencor)
Puma
 
 
 

If broadleaf weeds are a problem in the field, Huskie is a new broad spectrum herbicide, without the volatility issues of growth regulator herbicides such as 2,4-D and dicamba. Research has shown it to be effective against prickly lettuce and kochia, plus many others. Huskie should be ground applied at the 11 – 15 oz rate with a spray volume of 10 or more gallons per acre. Other herbicides are also available and a partial list can be seen in Table 1. If 2,4-D is used, the less volatile amine salt formulation is recommended.


 

A partial list of common growth regulator herbicides and other herbicides that can injure grapes is found in Table 2.

Table 2. Herbicides that have potential to injure grapes.

Growth regulators
 
ALS inhibitors
 
2,4-D
Dicamba
Others
Glyphosate
Sulfonylurea
Imidazolinone
Others
Amine 4
Banvel
Bronate*
Roundup
Ally
Arsenal
Gramoxone
Barrage
Clarity
Crossbow*
Rodeo
Ally Extra
Assert
Aim
Esteron 99
Rave*
Curtail*
Roundup Ultra
Amber
Beyond
Boa
Formula 40
 
Landmaster*
Roundup
Canvas
Pursuit
 
Hi Dep
 
MCPA
   UltraMax
Cimarron
Raptor
 
LV-4
 
RT Master
Roundup
Express
Plateau
 
LV-6
 
Starane
   WeatherMax
Finesse
 
 
Saber
 
Tordon
Landmaster*
Glean
 
 
Salvo
 
Turflon
Glyphos
Harmony Extra
 
 
Savage
 
Trimec
Glypro
Harmony GT
 
 
Tricep
 
WideMatch
RT Master
Oust
 
 
Weedar 64
 
 
Touchdown
Peak
 
 
Weed-B-Gone
 
 
 
Rave*
 
 
Weedmaster
 
 
 
 
 
 
Weedone
 
 
 
 
 
 

This list is not all-inclusive; other herbicides also may injure grapes.

*A prepackage mixture containing a growth-regulator herbicide as at least one active ingredient.

 

For additional information on preventing herbicide drift the following publications are available on-line: EM 8860 Preventing Herbicide Drift and Injury to Grapes (/files/em8860.pdf) and EM 8737 Preventing Phenoxy Herbicide Damage to Grape Vineyards. For more information visit OSU Extension CerealCentral.

 
 
 
keyword: